Liquid line indicator



Jan. 5, 1954 R. A. GRAY, JR 2,664,846

LIQUID LINE INDICATOR Filed Nov. 27, 1951 ||y z if IN V EN TOR.

Patented Jan. 5, 1954 LIQUID LINE INDICATOR Robert..A. Gray,.Jr.,fPortHuron,.Mich., assigner to MuellerlBrass Company, Port Huron, Mich., yacorporation of Michigan Application'Novembrcr 27, 1951, VSerial No.258,409

7 Claims. A1 c This Yinvention 'relates generally to sight glassres :or'indicators vand more particularly to such 'an indicator which .is"particularly adapted for 'use fin a lrefrigerant liquid line.

`object of `this invention is toprovide a new `and :improved liquid lineindicator of the-chai.` acter described.

.Anotherobject .of this invention is to provide such an indicator inwhich provision is made to compensate forlthe'unequal expansion andcontraction of the variousmaterials which comprise .the indicator.

y.Afurther object of `thisinvention is to provide such .an indicatorwhich will retard, if not entirely prevent, the escape of refrigerant inthe 4event 'ofthe rupturing of the transparent material used in theindicator.

- Another object of this invention is to provide `means for preventing:accidental 'injury to the transparent portion of the indicator duringperiods when itis `not desired to view the fluid iiowing 'through theindicator.

-Other .objectsof this invention will be apparent from `the.speciiicatioin vthe appended claims and the drawings, in which drawing:

Figure lisa view of .the indicator embodying the invention;

Fig. v2 is aview taken substantially along the vlines of .2 2 of Fig. i;

.Fig :3 is aview 'taken substantially `along the D Fig. 4 :is .aviewltaiten substantially along the lines of 4 4 of Fig. 2; and,

Fig. `5 `is a-'view similar to Fig. 1 but showing Ytheprotecting bodyportion moved outwardly to permit viewing of ithe iiuid flowing throughthe indicator.

Referring to the drawings vby character refn erence the numeral lindicates kgenerally an indicator `which is arranged to be inserted in ailuid `conduit vso that `the iiuid in the conduit may be observed. Theindicator maybe used for observing many different types or" fluids andforzpurposes of illustration it will be described in connection with aliquid line of a reirigerating system but such description should betaken as illustrative rather than limitative since it will be apparentthat 'it is equally adapted for conn duits containing other Fluids. Theindicator l comprises .a `first body 2, a `second body 4, and a e Vsleeve 5 which 1s arranged forsllding movement with respect to thebodies 2 and 4. The body 2 comprises a cylindrical portion 8 having anen larged portion it, which maybe hexagonal in cross section, adjacentVone end `portion thereof -whichxis adapted for receiving a wrench orother tool whereby its male fitting l2 may be screwed -2 to a suitablemating iitting on conduit (not shown). The male 'iitting l2 extendsoutwardly of the hexagonal portion Hl. vThe body 2 isprovided with achamber Ii which is preferably circular in crosssectionwhich is incommunication 'with a smaller' diameter passageway I6 extending throughthema'le fitting l2. The portion 20 or" the chamber 'i4 adjacent theinner end I8 of the body/2 is of a larger diameter and receives a.reduced diameter cylindrical end portion 2'2 of the body 4.

The body Il is provided with a chamber 24 having a reduced diameterportion26 opening outwardly through the outer end 28 of the body 4.having a slightly larger diameter portion 39 opening outwardly throughthe inner end 32 of the body 4. `The normal diameters of the chamber I4and of the chamber portion Sil of the body 4 are substantially equal andare aligned to .receive .opposite end portions of a short piece `oftransparent tube V35i, which preferably is glass. One or 'more portionsof the side walls of the lcylindrical jportion 8 of the vbody 2 `are cutaway to provide lopenings 34 which permit the viewing lof a iiuid withinthe tube :35 through an intermediate side wall portion 42.

The body 4 has a portion 44 which is ofthe same external size 'as theportion 8 of the body .2 whereby the `sleeve 6 may be slid along thebodies to Vcover the aperture 34. Preferably the portion -8 of the body2 is provided with the peripheral slot 4S which receives an O-typesealing vring 43 which, with the sleeve t in the position shown in Figs.Vl and 2, acts to prevent iluid .flow ybetween the body `2 and thesleeve S. Similarly the portion v44 Aof the body 4 is provided `with aperipheral aperture il'which receives another O-type sealing ring 52 forpreventing iow of huid between the sleeve 6 and the body 4. in order-that 'the diameter 'of the indicator i may made assmall as possible andthe sleeve t arranged to slide longitudinally with respect to the bodiesA2 and 4 to expose the tube t to external view, a short section of tubning Sii is secured within the chamber portion 26 of the body il andextends outwardly from the body 4 a distance suiiicient to permitsliding movement of the sleeve .8 longitudinally of the bodies 2 and The`far end of the tube 54 may be provided with a flared end 56 and flarenut 5i? for securing the tube 54 to the conduit section of a refrigerantor other fluid system.

The transparent tube 36 is preferably glass and may be of the type inwhich its opposite end portions are covered with a metallic Amaterial sothat these Iends may Ibe soft soldered into Athe bodies 2 and 4.Normally the strength of the glass tube 36 is suiiicient under normalexpected pressures in the fluid system to hold the body portions 2 andIl in the desired lrelative position. The telescopically arrangedportions of the bodies 2 and l are provided with aligned annular grooves60 in which is positioned a snap ring 62. As will be apparent from thedrawings, the width of the snap ring $2 is less than the width of theannular aperture 60 so that normally the positioning of the body fl withrespect to the body 2 will be determined solely by the glass tube 36 andthe bodies 2 and i may have limited relative movement to compensate forthe diierences in the coemcient of thermal expansion between the metalof the bodies and the glass tube 35. However, in event of rupture of theglass tube 35, and relative movement oi the bodies 2 and ll, the snapring 52 will engage the shoulders of the annular recess Si? and preventoutward movement of the body member d from the body 2. Preferably thethickness of the snap ring E2 is such that it may be received entirelywithin the portion of the annular recess Sil which is within the body ithereby permitting initial assembly. After assembly, the snap ring E2has sufficient resilience to snap out and into the position shown in thedrawing in which the body 4 is prevented from withdrawal outwardly ofthe body '2.

With the sleeve 5 in the position of Fig. l, rupturing of the tube 36will not result in a rapid loss of refrigerant and in many circumstancesthe sleeve 6 will fully seal the rifrig'erant systems and no loss ofrefrigerant will result since the opening formed by the rupture will besealed by the O-rings llt and 52.

What is claimed and is desired to be secured by United States LettersPatent is as follows:

'1. A fluid line indicator comprising first member having a passagewayextending therethrough and having an end portion, said member having anaperture through a wall thereof opening into said passageway, a secondmember having a passageway and having an end portion, said end portionsbeing constructed to be telescoped together, lost-motion locking meansholding said telescoped end portions together and permitting limitedrelative movement therebetween, a transparent tubular member within saidrst member passageway having an intermediate portion viewable throughsaid aperture, and means immovably securing and sealing one end portionof said tubular member to said first member and immovably securing andsealing the other end portion of said tubular member to said secondmember and spacing said first and second members to an intermediateposition of said lost-motion means whereby the distance between saidiirst and second members throughout the range of said lost-motion meansby any change in length of said tubular member is determined solely bysaid transparent mem- A ber.

elongated body having means adapted for securing one end of said body toa uid conveying conduit, said body having an elongated second portionwith a cylindrical outer surface, said body having an internal boreextending therethrough and opening outwardly of the end of said bodyopposite to said one end, said bore having a normal diameter portionspaced from said opposite end and an enlarged diameter portion openingoutwardly of said opposite end, a transparent tubular member within saidbore and having a rst end portion immovably secured and sealed to saidnormal diameter bore portion and a second end portion extending towardsaid body opposite end, a second body having a iirst portion with acylindrical outer surface, said portion being telesooped within saidenlarged bore portion, lost-motion locking means holding said bodiesagainst more than a predetermined amount of relative movement therebetween, means immovably securing and sealing a second portion of saidtubular member to said second body, said first body having an apertureopening through said elongated second portion and into said rst bodybore whereby a portion of said tubular member intermediate said tubularmember iirst and second portions may be viewed.

5. The combination of claim 4 in which a cylindrical sleeve is provided,said sleeve being movable relative to said bodies into and out of aposition covering said aperture, and in which means is provided forsealing said sleeve to said bodies to prevent :duid flow along saidsleeve and outwardly of said bodies in the event of rupture of saidtubular member.

6. A fluid line indicator for iluids subject to change in temperaturecomprising a iirst hollow elongated body, a second hollow body, saidsecond body having a portion telescopically received within the hollowinterior of said first body, lostmotion locking means holding saidbodies within predetermined limits of relative movement, a glass tubewithin the hollow interior oi said bodies, means immovably securing andsealing one end portion of said tube in fluid tight relation to saidfirst body and another end portion of said tube in iluid tight relationto said second body, at least one of said bodies being apertured topermit the viewing of a portion of said tube intermediate said endportions from the exterior of said bodies, said tube end portions beingso chosen that at normal room temperatures said tube acts to relativelyposition said bodies at an intermediate position of said lost-motionlocking means.

'7. The combination of claim 6 in which a sleeve is provided formovement relative to said bodies and movable into and out of a positionin which said sleeve covers said body aperture whereby it is operable toprotect said tube from accidental injury, and sealing means cooperablewith said sleeve when said sleeve is in a position to cover said bodyaperture to prevent escape of fluid from said indicator in the event ofrupture of said tube.

ROBERT A. GRAY, JR.

References Cited in the le of this patent UNITED STATES PATENTS WittlinJune 10, 1952

